Soldering iron



Patented May 11, 1926.

UNITED STATES FRED MORGAN, OF CHICAGO, ILLINOIS.

SOLDERING IRON.

Application filed January 22, 1923. Serial No. 614,159.

This invention relates to improvements in devices such as soldering irons employing electrical heating units. Y

The object of the invention ist-he provision of a device of this character which shall be cheap to manufacture, easy to assemble, durable, and efficient in operation.

"One of the features of the inventionk vis the provision of' a heating Vunit consisting of' a bar of resistance'material which'is longitudinally slotted throughout the greater portion of its length,jthus providing a resistance device which is practically indestructible from overheating, and which will vnot be fractured by any of the blows or jars to which a device of this kind would ordinarily be subjected.Y

Another feature of the invention is he manner of attaching the leading in conductors to the extreme ends of the resistance element which is hairpin or U-shaped, thus avoiding the use of the commonly employed return conductor which frequently becomes brittle and breaks.

Another feature of, the invention is` the arrangement of the heatingv unitl within a jacket of insulating refractory'material, which in turn is enclosed in the metallic head, thus fullyA protecting the heating unit.

A still further feature of the invention resides in the arrangement of a sheath of heat insulating material about the sides and one end of the heating unit, and the metallic sleeve withinI which it is located, thus directing the heat generated towards the tip or working portion of the device.

Other features and advantages will appear from time to time as the description of of the invention progresses.

It is believed the, invention will be best understood by: a description thereof taken in connectionwith the accompanyliigdrawings, in which Figure 1' is a side view of applicants 'sol-dering iron fully assembled;

Figure 2 isa longitudinal section through the device; i Figure 8 shows a section substantially on the line 3 3 of Figure 2, and s Figure 4 is a section through the head of a slightly modified form of iron. f

Referring now to the drawings, in whichv like reference characters indicate like parts :in the several views,` 5 indicates a metallic 'cylinder or sleeve of suitable conducting 'material Within the bore of the cylinder 5 is the heating element 6 which consists of a non-metallic resistance material, preferably of a silicon-carbide mixture combined with suitable binders and corrective elements. The element 6 is in the nature yof nally Vslotted down the middle through the Vgreater portion'of its length. The slot 7 a cylindrical bar which has been longitudil 5, is filled with asuitablev insulating refraci tory material. indicated at 8.

One end o-f the sleeve 5 is screw threaded and has the adjusting and holding nut 9 threaded therein. Also in yscrew threaded engagement with the threads at the end of v the member 5 is the tip member 10.

Positioned about' the insulating refractory material 8 adjacent to one end of the collar 5 is a washer 11 of suitable heat insulating Beyondthewasher 11, the legs g material. of the resistance element 6 are slightly flattened on the outer sides. Surrounding the flattened portions 12 of the resistance element is a metallic sleeve 13 between which and the portion 12 vare the blocks 14 of in-A v sulating material.' Between the blocks 14 and the flattenedends 12 of the resistance element are inserted the flattened ends 15 of the electrical' conductors. The screws 16 are threaded through the sleeve 13 and bear against the blocks 14, thus firmly clamping the ends 15 of the conductors between the blocks 14 and the flattened ends 12 of the resistance element..

Positioned within the shouldered portion 17 0f the cylinder 5 is a sleeve 18 of heat insulating material. Abutting the end of the sleeve 18 is a disc 19 of heat insulating material. The disc 19 is provided with the openings 20 throughwhich the conductors 21, which terminate in the flattened portions 15, extend. Y

Secured to the. shouldered portion 22 of the cylinder 5, by means of the screws 23, is the metallic sleeve 24. Within the opposite end of the sleeve 24 there is secured, by means of the screws 26, a bushing 27 which abuts against the insulating disc and maintains it in position.

The bushing 27 is screw threaded, and

Y'the metallic tube 28 has screw' threaded enthe conductors 21 extend.

Positioned about the end of the tube 28 remote from the soldering iron head is the handle member 3l. The member 3l is provided with a ferrule 32. The screws 33 have screw threaded engagement with the ferrule 32 and pass through the end portion of the handle member 3l and into engagement with the tribe 28, thus firmly securing the handle to the tube 28. rlhe handle member 3l has a reduced screw threaded portion Se on which is screwed the handle member 35. Member 35 is provided with a cavity 36 within which is a block 3'1" of insulating material which carries the binding posts 38. The terminals of the conductor pair 89, and also the ends of the conductors 21 are respectively secured on the binding posts@ by means of the nuts a0.

As the form of the device shown in Figure l is the same as that shown in Figure 2, with the exception of certain details, only the manner in which this device differs from the one already described will be explained.

In engagement with the heat insulating disc 19 is a washer tl of electrical insulating material. Carried by the washer il are the binding posts ft2 which receive the ends of the leading in conductors h3 and also of the conducting elements lill, the opposite ends of which are clamped into engagement with the ends of the resistance element 6 by means of the screws 16, as above described.

The bushing Ll5 differs from the bushing 27 of Figure 2 in that it has no flange proj ecting forwardly toward the heat insulating disc 19. In the present embodiment, a sleeve 46 of heat insulating material is arranged between the end of the bushing 45 and the insulating element 4l, Screw threaded into the inner end of the bushing 45 is a flanged collar i7 of heat insulating material.

It will thus be seen that in the present arrangement, the heating element is arranged with its terminals remote from the tip of the iron and adjacent to each other, thus making unnecessary the use of a return conductor such as commonly employed. WWhile the heating element is itself of very durable construction, the arrangement of this ele- .ment within the core of the cylinder 5, and the provision of the refractory material 8 between it and the cylinder, act to so protect the heating element that there is practically no danger of it becoming broken due to jars. It will also be noted that the heating element is practically entirely surrounded by a sleevefof heat insulating material, and that the end of the device remote from the tip is also closed, thus acting to force the heat to escape at the end adjacent to the soldering tip.

While the drawings and the above description have been confined largely to a single mettere set of details, it is to be understood that many modications are contemplated and the invention, therefore, should be limited merely by the scope of the appended claims.

Having thus described my invention, what claim as new and desire to secure by Letters Patent of the United States is:

l. ln a device of the class described, metallic head having a cavity therein, a heating element consisting of a bar of resistance material within said cavity, said bar being longitudinally slotted throughout the greater portion of its length, refractory insulating material between said element and said head, and leading in conductors electrically joined to the ends of the portions of said bar separated by the slot.

2. In a device of the class described, a metallic head having a cavity therein, a heating element consisting of a bar of nonmetallic resistance material within said cavity, said bar being longitudinally slotted throughout the greater part of its length, refractory insulating material in said slot and about said element, and leading in conductors electrically joined to the ends of the portions of said bar separated by the slot.

3. ln a device of the class described, a metallic head having a cavity therein, a resistance heating element consist-ing of a bar of silicon-carbide composition within said cavity, said bar being longitudinally slotted throughout the greater part of its length, and leading in conductors electri cally joined to the ends of the portions of said bar separated by the slot,

et. ln a device of the class described, a tubular metallic head, a heating unit consisting of a bar of silicon-carbide composition within said bar, a tip within said head and projecting therefrom, said bar being longitudinally slotted throughout the greater part of its length remote from said tip, refractory insulating material in said slot and about said unit, and leading in conductors electrically joined to the ends of the portions of said bar separated by the slot.

5. ln a device of the class described, a metallic head having an axial opening, a U-shaped non-metallic heating unit within said axial opening, electrical conductors connected to the ends of said unit, electrical insulating material between said heating unit and the side walls of said axial opening, a tip at one end of said head, and a sheath of insulating material surrounding the sides and the end of said head remote from said tip..

G. In a device of the class described, a head, a heating element within said head, said element consisting of a bar of nonmetallic resistance material longitudinally slotted throughout the greater part of its length, leading in conductors having terminals adjacent to the free ends of said resistance element, insulatinlg blocks overlying said terminals, and screws for acting on said blocks to clamp said terminals respectively in engagement With the ends of said resista-nce element.

7. In a device of the class described, a head, a heating element Within said head, said element consisting of a bar of nonmetallic resistance material longitudinally slotted throughout the greater portion of its lengt-h, leading in conductors having ter niinals adjacent to the free ends of said resistance element, insulating blocks overly ing said terminals, a metallic ring surrounding said blocks and screw threaded through said ring and acting on said blocks to clamp said terminals respectively in engagement with the ends of said resistance element.

8. In a device of the class described, a tubular metallic head, a heating element consisting of a bar of non-metallic resistance material Within said head, a tip Within one end of said head and projecting therefrom, said bar being slotted throughout the greater portion of lits length remote from said tip, leading in conductors electrically joined to the free ends of the portions of said Vbar separated by the slot, a heat insulating sleeve surrounding the portion of said head containing said resistance element, and a disc of heat insulating material' Within said sleeve at the slotted end of said bar. t

9. In a heating device, a heating element consisting of 4a bar of resistance material, said bar being longitudinally slotted throughout the greater portion of its length, and leading-in conductors electrically joined to the ends of the portions of said bar separated by the slot.

' 10. In a heating device, a resistance element consisting of a bar of non-metallic resista-nce material longitudinally slotted throughout the major portion of is length, leading-in conductors having terminals adjacent to the free ends of said resistance element respectively, insulating blocks overlying said terminals, a metallic ring surrounding said blocks, and screws threaded through said ring and acting on said blocks to clamp said terminals in engagement With the respective ends of said resistance element.

11. In a device of the class described, a metallic head having a cavity therein, a heating element consisting of a bar of resistance material Within said cavity, said bar being longitudinally slotted throughout the greater portion of its length, and leading in conductors electric-ally joined to the ends of the portions of said bar separated by the slot.

12. In a device of the class described, a hollovv metallic head, a heating unit consisting of a bar of silicon-carbide composition Within said head, said bar being longitudinally slotted throughout the greater part of its length, and leading-in conductors electrically joined to the ends of the portions of said bar separated by the slot.

13. In a device of the class described, a metallic head having a central opening, a U-shape'd heating unit Within the central opening, insulating material imbedding said heating unit in said central opening, a tip .detachably secured Within said head at one end thereof and a sheath of heat insulating material surrounding the sides and the end of said head remote from said tip.

In Witness whereof, I hereunto subscribe my name this 18 day of January, 1923.

FRED MORGAN. 

